1. Columbus discovered America.
America was discovered by Columbus.
2. We keep money in a safe.
Our money is kept in a safe.
3. A bee stung her.
She was strung by a bee.
4. They speak Italian in Italy.
Italian is spoken in Italy.
5. They have taken his aunt to hospital.
His aunt has been taken to hospital by them.
6. The boys damaged the television.
The television was damaged by the boys.
7. Da Vinci painted the Mona Lisa.
The Mona Lisa was painted by Da Vinci.
8. He invited 30 people to his party.
30 people were invited by him to his party.
9. They grow bananas in Africa.
Bananas is grown in Africa.
Объяснение:
1. В нашей стране происходят большие перемены. 2. Проблема человека и его взаимодействия с окружающей средой – одна из самых серьезных. 3. Не так давно ростовчане отметили свое 250-летие. 4. Энергетический кризис показал необходимость поиска новых источников энергии.